This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The study examines dystonia and the hypothesis that persons who demonstrate dystonic symptoms, as compared to healthy subjects who do not have such symptoms, have overactive cortical plasticity, and thus a relatively lower incidence of the BDNF val66met genotype variant. The specific aim of the current study is to compare the frequency of the BDNF val66met genotype in persons diagnosed with dystonia to the frequency in healthy, non-dystonic controls. As a secondary aim, both subject groups will also be tested for the presence of the mutation in the DYT1 gene. The subhypothesis is that among the rare dystonic subjects who have the DYT1 gene mutation the absence of the val66met mutation in one or both alleles will be associated with an earlier age of onset and more severe level of dystonic symptoms, as compared to dystonic patients who carry this mutation. Note that one control group will be age-matched, healthy subjects. A second control group will be subjects with Parkinson's disease, also a basal ganglia disorder, but, unlike dystonia, due to neurodgeneration and with a pathophysiology presumed different than idiopathic dystonia.